$ git clone -n https://src.fedoraproject.org/rpms/rust-num-complex.git /var/lib/mock/f39-build-1494036-34542/root/chroot_tmpdir/scmroot/rust-num-complex
Cloning into '/var/lib/mock/f39-build-1494036-34542/root/chroot_tmpdir/scmroot/rust-num-complex'...
$ git fetch origin 775b1db15108b72cb5951899f09dd3be837d4c87:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-num-complex
 * [new ref]         775b1db15108b72cb5951899f09dd3be837d4c87 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 775b1db Update to version 0.4.4; Fixes RHBZ#2231759